One idea could be a story where a character from 'Game of Thrones' is transported into the world of 'For Honor' and has to adapt to its combat styles. For example, Jon Snow finding himself in the middle of a battle in 'For Honor' and using his skills to survive. He might form alliances with the different factions in the game, much like he did in Westeros.
A fanfiction could focus on the houses in 'Game of Thrones' being represented as different factions in 'For Honor'. The Stark family could be like the Knights, with their sense of honor and loyalty. The Lannisters might be more like the Samurai, with their political cunning and wealth. This could lead to epic battles between the different 'Game of Thrones' - inspired factions in the 'For Honor' world.
Perhaps a fanfiction where a powerful weapon from 'For Honor' makes its way into the hands of a 'Game of Thrones' character. Let's say Arya Stark gets hold of a unique sword from 'For Honor'. She then uses it to take revenge on her enemies in Westeros in new and exciting ways. The sword could have special abilities that add a new dimension to her already impressive skills.
One idea could be a story about a young knight from one of the factions who gets separated from his comrades during a battle. He then has to survive in enemy territory and in the process, he discovers a hidden conspiracy within the enemy's ranks. He must then decide whether to use this knowledge to his advantage in the ongoing war or to try and expose it to bring about peace.
One idea could be exploring what would happen if a minor character, like Gendry, had a more prominent role in the story. He could potentially become a powerful lord and change the political landscape.
A great idea for 'Game of Thrones fanfiction' is to rewrite the story from the perspective of the smallfolk. For instance, how did they really feel during all the wars and power struggles? How did the common people in King's Landing cope with the different rulers? You could also explore a fanfiction where the White Walkers are not the villains. What if there was a misunderstanding and they were actually trying to protect the realm from some other greater threat?
One idea could be exploring what would happen if Jon Snow was raised by the Starks as a trueborn son. Another could be a fanfiction about Daenerys Targaryen's journey if she had made different alliances earlier. Or perhaps a story about Arya Stark training with a different master assassin.
One idea could be exploring what would happen if a minor character like Gendry had been secretly trained in magic. He could use his newfound powers to unite the smallfolk against the warring nobles. Another plot could revolve around a female knight from the North who disguises herself as a man to fight in the wars, and along the way, she discovers secrets about the White Walkers that no one else knows. Or perhaps a fanfiction where Daenerys and Sansa form an alliance much earlier and together they reshape the power dynamics of Westeros.
A cool fanfiction concept could be a situation where the magic in Game of Thrones has an impact on Smallville. Suppose a powerful sorcerer from Westeros accidentally opens a portal to Smallville. This could lead to all kinds of chaos as the residents of Smallville have to deal with magic they've never seen before. On the flip side, the Kryptonians' powers could be seen as a threat in the eyes of the Game of Thrones characters, leading to a potential conflict. Or perhaps some of the noble houses in Westeros could try to form alliances with the powerful beings in Smallville for their own political gain.
A possible idea is to have a character like Daenerys Targaryen receive visions similar to those in the Bible. These visions could guide her in her quest for the Iron Throne, but also make her question her actions and power-hungry nature. It would be an interesting take on her character development.
An interesting 'oc game of thrones fanfiction' could focus on an OC who is a female knight in a world dominated by male warriors. She could face discrimination but also prove herself in tournaments and battles. Maybe she becomes a trusted ally of a major character like Jon Snow. Or you could have an OC who is a bard that spreads tales which either inspire or deceive the people of Westeros. Also, an OC who is a foreign diplomat trying to broker peace deals between the warring factions while having their own hidden agenda would be a great concept.
One idea could be Loki somehow being transported to the world of Game of Thrones and using his magic to manipulate the political intrigue. He might side with a particular house and use his wits to outsmart their enemies.
One idea could be to combine the magic systems. For example, in Warhammer there are powerful spells and in Game of Thrones there is magic like that of the Red Priests. You could have a character who is a hybrid of a Warhammer wizard and a Game of Thrones maegi, creating new and unique magical abilities and storylines. Another idea is to merge the political intrigue. The complex power struggles in Game of Thrones and the different factions in Warhammer could lead to some really intense and convoluted political plots. For instance, the different Chaos factions could be like the different Houses in Westeros, all vying for control and power.